package com.solver.aspect;

import com.solver.annotation.AutoFill;
import com.solver.constant.AutoFillConstant;
import com.solver.context.BaseContext;
import com.solver.enumeration.OperationType;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.time.LocalDate;
import java.time.LocalDateTime;

@Aspect
@Component
@Slf4j
public class AutoFillAspect {
    /**
     * 切入点
     */
    @Pointcut("execution(* com.solver.mapper.*.*(..)) && @annotation(com.solver.annotation.AutoFill)")
    public void autoFillAspectPointCut(){}

    /**
     * 前置通知
     * @param joinPoint
     */
    @Before("autoFillAspectPointCut()")
    public void AutoFill(JoinPoint joinPoint){
        log.info("前置通知");

        //获取到当前被拦截的数据库操作方法的类型
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();//获取方法签名对象
        AutoFill autoFill = signature.getMethod().getAnnotation(AutoFill.class);//获得方法上的注解对象
        OperationType operationType = autoFill.value();//获取数据库的操作类型

        //获取被拦截方法的参数，如teacher
        Object[] args = joinPoint.getArgs();
        if(args.length == 0 ||args ==null){
            //防止空指针
            return;
        }
        Object entity = args[0];//注意，mapper的方法应该把需要处理的参数放在第一位，如teacher、question

        //准备需要赋值的数据
        LocalDateTime now = LocalDateTime.now();
        Long currentId = BaseContext.getCurrentId();

        //根据不同的操作类型 为对应的属性赋值
        if(operationType == OperationType.INSERT){
            //赋值四个公共字段
            try {
                Method setCreatTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_TIME,LocalDateTime.class);//通过常量引用方法名，防止手敲出错
                Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME,LocalDateTime.class);
                Method setCreatUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_USER,Long.class);
                Method setUpdateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER,Long.class);
                //通过反射赋值
                setCreatTime.invoke(entity,now);
                setCreatUser.invoke(entity,currentId);
                setUpdateTime.invoke(entity,now);
                setUpdateUser.invoke(entity,currentId);
            } catch (Exception e) {
                e.printStackTrace();
            }

        } else if (operationType == OperationType.UPDATE) {
            try {
                Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_TIME,LocalDateTime.class);
                Method setUpdateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER,Long.class);
                //通过反射赋值
                setUpdateTime.invoke(entity,now);
                setUpdateUser.invoke(entity,currentId);
            } catch (Exception e) {
                e.printStackTrace();
            }

        }

    }
}
